If you’re going to attempt to humanize the border between two contentious countries, you should probably start by asking the humans living there what they think.

And while it’s easy (well, relatively) to go in and ask the first migrants or border guards or vendors that you see — doing your engagement homework beforehand doesn’t hurt either. That was the premise of Borders, Vox’s video series by Johnny Harris and producer Christina Thornell.

After living near the U.S.–Mexico border in Tijuana, “I wanted to humanize the lines on the map,” Harris said. “I wanted to look at a map and zoom into it and look at the people there and the stories surrounding this thing that we usually just look at from 30,000 feet.”

Harris, an international-relations aficionado, pitched the idea a few years ago, which has since bubbled into three seasons of five or six episodes. The first season focused on six different borders from Haiti/Dominican Republic to Nepal/China. The second, a deep dive into Hong Kong, brought in more engagement reporting — to avoid the white-man-parachuting-into-the-natives’-land trope and more fully telling the stories of Hong Kong’s borders. The third — focusing on the borders of Colombia — is yet to come, as the callout started Thursday with the Harris’s announcement of the new destination.

Vox’s video team is only four years old, like the site itself; its leader, Joe Posner, pointed out that Harris was the fourth person to join the team. “It’s a delicate mission to help explain the world, but we’re just riding along with our audience. We’re just as curious as they are,” Posner said.

This isn’t the first time Vox (with a four-person engagement team) has sought its audience’s ideas for video; for Explained, its weekly Netflix show, producers used follower input for its e-sports and K-pop episodes, Posner said. Vox also made a video on what high schoolers really think about school shootings drawing from a survey after the Parkland shooting with 1,635 responses.

The Borders idea was different because the approach was baked in from the beginning. “I was sensitive to saying, ‘Here I am, an outsider, a non-expert going to these places and saying I’m here to explain this,'” Harris said.

Blair Hickman, Vox’s director of audience, explained the way they ramped up engagement with each season. For the first, knowing it would have a broader focus, Harris made a video asking followers to suggest places for him to highlight. Hickman designed a form to gather ideas and 7,000 responses came in over one month. While Harris was out exploring, the engagement team flexed the muscles of Harris’s Facebook page as a “community hub,” as Hickman described it, to share his trip with the 69,000 followers.

For the second season on Hong Kong, Harris and Hickman created a network of local followers who wanted to participate in or help the videos’ creation in some way, using this form and other callouts. “We expected 40 responses and got more than 700,” Hickman said. “In the weeks leading up to his trips, each week we would send via email a set of structured call-outs for what to explore.” These were designed to both hopefully find interviews on the ground and local fixers to help navigate the politics of drone-filming borders, but also surface other components of the larger story of the border, like a neon light craftsman and people stuck in cage homes in Hong Kong’s housing market. When he was on the ground, Harris emailed the network to see if anyone wanted to meet up and had to make a waitlist with 400 interested people. He set up a meeting place with 15-minute slots to come chat with him, and ended up walking around with some folks who described the history of the locations to him as they lived through it. But all the work started beforehand.

“Going through and reading 400 responses to people’s feelings on the encroachment of China in Hong Kong, suddenly after you read hundreds of responses on how people are thinking about this — you haven’t set foot in Hong Kong but you’ve interacted with this paradigm,” Harris said.

Now the show moves onto Colombia, but the network in Hong Kong remains. Hickman said they hope the local audience stays interested in the Borders framework and continues to watch the next season, and that Vox will be able to rely on them for help sourcing future stories. But the stories Harris tells in the next season depends on the ideas they get from the people who live there.

Vox’s video programming has remained scrappy, as we described in a piece about the team midway through its current existence, with a streamlined focus on having one person responsible for the video — from pitch to publication. Besides their Netflix foray with Explained, they’ve also leaned on Facebook Watch both for funding and increased viewership. “More broadly we are just trying to grow onto the various stages for video that exist,” Posner said.